Hello,

I'm using Shaft Component Generator for the first time and I have some questions. Would greatly appreciate help understanding some terminology.

I'll have a cylindrical shaft supported by two pillow block bearings (probably double row spherical roller because there are both axial and radial loads on the bearings). One end of the shaft extends through a non-expansion type bearing and attaches to a tumbling barrel. There is a step in the shaft (increases in diameter) on the tumbling drum side of the bearing. There is a shaft collar on the other side of the non-expansion type bearing to prevent axial movemet of the shaft in the bearing. There are also set screws in the bearing that will be tightened on the shaft. A hollow bore gearmotor will be mounted between the two bearings. The other end of the shaft (opposite the tumbling barrel) is secured in an expansion type bearing (set screws in the bearing).

When using the Shaft Component Generator, I placed a Fixed Support at the location of the bearing on the tumbling barrel end of the shaft because the bearing is trapped between the step in the shaft and the shaft collar. I placed a Free Support at the location of the other bearing because it is an expansion type bearing.

My first question pertains to the Fixed Support. Am I correct thinking even tough it is called a Fixed Support, it actually behaves as though it is a fixed pinned connection? I feel this is the case when I look at the Deflection Graph. If it was truly fixed, there would be no shaft deflection on side opposite the tumbling barrel.

Am I correct thinking the Free Support also behaves as though it is a fixed pinned connection, but the Free Support is stationary and the shaft is allowed to move with respect to the location of the Free Support?

I’d also appreciate comments regarding . . . I compared Shaft Component Generator graphs for two 2” diameter x 18” long shafts, with a load at one end, a Free Support at the other end and a Fixed Support near the center. The only difference between the two shafts is one has a 5” long keyway. I looked at the graphs for Shear Force, Bending Moment, Bending Stress, Reduced Stress and Ideal Diameter. They are all identical. What really troubles me is the mass of the shaft with the keyway is identical to the one without the keyway. Is the keyway ignored? What use is the Shaft Component Generator if it doesn’t take features like keyways into account?

Kind Regards,
JMK